Abstract: Examples of the present disclosure describe systems and methods for implementing a confidential virtual machine generation system. In examples, read-only and read-write volumes are generated to store operating system binaries and user-generated content, respectively, on filesystems indexed using hash trees. The hash values of the roots of the two hash trees are stored in a location accessed as part of loading an operating system. The example system accesses the roots of the two hash trees to access the current state of read-only and read-write volumes and verify the states using a checksum. The verified states are merged to generate an operating system image associated image with the confidential virtual machine. Additionally, the system merges the namespaces of filesystems of read-only and read-write volumes into a single filesystem namespace concealing multiple volumes.

Abstract: Examples of the present disclosure describe systems and methods for implementing a confidential virtual machine generation system. In examples, read-only and read-write volumes are generated to store operating system binaries and user-generated content, respectively, on filesystems indexed using hash trees. The hash values of the roots of the two hash trees are stored in a location accessed as part of loading an operating system. The example system accesses the roots of the two hash trees to access the current state of read-only and read-write volumes and verify the states using a checksum. The verified states are merged to generate an operating system image associated image with the confidential virtual machine. Additionally, the system merges the namespaces of filesystems of read-only and read-write volumes into a single filesystem namespace concealing multiple volumes.

Abstract: The state of a file may be a combination of local state, typically small (e.g., a placeholder file), and some external source state such as that maintained in a read-only namespace managed by a cloud provider or by another local file system, typically large. A file system component responsible for overlaying (i.e., merging) the partial local state and the external source state into a single file system view that can be used by an application of a container as if the full state exists locally. Overlays that comprise the file system state may be referred to as “layers”. A tombstone mechanism may be provided to record delete or rename modifications in the top layer.